Eiji Aonuma has come out on Miiverse and announced that Majora's Mask 3D has been in-development since 2011 when they wrapped up Ocarina of Time 3D.
A couple of things to note here based on that:
- That's more time than Ocarina of Time 3D spent in development
- The original Majora's Mask on the N64 was, famously, built in a year
Eiji also added that, "although we've been working on the game for quite some time, we didn't want to say it was being developed until we were at a point where we could proudly say that this is not going to be just another remake and that it's going to be worth your time". And that changes and new features would be announced closer to the release date.
I know the game has its detractors, but I find the original to be near-perfect so there's not that much to improve upon really :P Plus borrowed assets from OoT3D. What have they spent all this time doing? I'd imagine they have a small team working on this maybe? In addition to Grezzo?
More dungeons? Maybe a Master Quest mode with new dungeon layouts? Gotta be something new in there if they've spent this long! o_o